Railway sidings are alternate routes created to accommodate railroad cars such as cargo and storage. Synonyms for railway siding include a spur, a branch line, a passing track, or a shunt. A spur is a short line or track branching off the main route. A branch line is a long track that leads to a smaller destination. A passing track is a section on the train track that allows two trains going in opposite directions to pass each other. A shunt is a section of the track where a locomotive can switch railway cars into a different siding. These synonyms provide alternative ways to describe an important aspect of railroad infrastructure.